import java.util.*;

public class test {

    public static boolean containsDuplicate(int[] nums) {
        for(int i = 0; i< nums.length; i++){
            int j = i-1;
            int temp = nums[j + 1];
            while(j >= 0 && nums[j] > temp){
                nums[j] = nums[j+1];
                j--;
            }
            if(j >= 0 && nums[j] == nums[j+1]){
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) {
        String s = "0P";
        System.out.println('a' ^ 'a');
        Deque<Integer> deque = new LinkedList<>();
        deque.add(1);
        deque.add(2);
        System.out.println(null != null);
        int[] nums = new int[]{1,3,2,3};
        System.out.println(containsDuplicate(nums));
    }
}
